Robots are electro-mechanical devices that can manipulate objects using a series of robotic links. The robotic links are connected to each other by joints, each of which may be independently or interdependently driven by a joint motor and/or another suitable actuator. Each robotic joint represents an independent control variable or degree of freedom. End-effectors, which are also referred to as manipulators, are the particular end links used to directly perform a given work task or skill such as grasping a work tool, stacking one part with respect to another, etc. Precise motion control through the robot's various degrees of freedom may be organized by task level: object level control, i.e., the ability to control the behavior of a grasped object, end-effector control, and joint-level control. Collectively, the various control levels cooperate to achieve the required robotic dexterity and work task-related functionality.
A modification to an object handled by a robot in the execution of a task sequence typically requires relatively expensive retraining of the associated control hardware. This tends to be true even if the grasped object surfaces themselves have not changed. Similarly, changes to the positioning of the object in the robot's surrounding work environment as a result of error and/or relaxed operating rigidity may also require expensive retraining. However, existing robot manipulator control software is not easily retooled to meet changing flexibility requirements.